Recent studies have concluded the selenium has great benefits to the human diet. Soils found in the Northern Plains have some of the largest natural amounts of selenium in the world. Crops grown in the Dakotas will contain larger amounts of natural selenium, than crops grown elsewhere. Beef grown in the area will also have higher amounts of selenium due to the local grasses and grains used as feed.

-Colvin

SDSU study: Selenium-rich feeds yield selenium-rich beef

Consumers can get most of the selenium needed to lower their risk of cancer from eating beef raised on selenium-rich forages like those that occur naturally in parts of South Dakota.

SDSU Extension Beef Specialist Cody Wright said that’s one finding from a study SDSU scientists carried out with the support of the South Dakota Beef Industry Council.

SDSU scientists are participating in similar studies looking at selenium and sheep.
Selenium can be toxic in large amounts, but trace amounts of it are necessary for cell function in humans and animals.

Some soils in South Dakota and neighboring states have high levels of selenium, which in turn is taken up by plants. That has traditionally been a problem for South Dakota producers because selenium poisoning can occur over time if livestock accumulate too much selenium from the forages they eat.

However, much of the world has the opposite problem, environments deficient in selenium. Selenium deficiency is linked to a fatal cardiomyopathy, Keshan disease. Animal studies have demonstrated that selenium can inhibit the formation of tumors, and human studies have supported such a role of selenium in cancer prevention.

Some South Dakota producers already have sold high-selenium wheat to buyers in Europe and Asia who are interested in the health benefits of selenium, and Wright said high-selenium beef could provide a similar opportunity.

“Because the supplementation of selenium to beef cattle is federally regulated, traditional feeds containing elevated concentrations of selenium have particular value,” Wright noted. “They are not subject to the federal regulation and could provide beef producers with a unique opportunity to increase the selenium concentrations in their beef and potentially develop a value-added market niche.”

Working with a commercial feedlot in central South Dakota, SDSU researchers formulated medium- and high-selenium diets from selenium-rich feeds grown in the area. They divided 90 crossbred steers into two groups and fed them on those diets for 79 days. After slaughter at a commercial plant, slices of beef were harvested from the longissimus dorsi between the 12th and 13th rib. The samples were then analyzed for moisture, fat, and selenium concentrations at SDSU’s Oscar E. Olson Biochemistry Laboratory.

Assuming that an adult human consumes a 3.5 serving of cooked beef a day, the SDSU study showed that a person could get 73.5 percent of the selenium that researchers believe is needed to reduce the risk of cancer simply by consuming beef from cattle fed the medium-selenium diet. By eating beef finished on the high-selenium diet, the consumer could get 83 percent of the selenium that is thought necessary to reduce the risk of cancer.

For comparison, the SDSU study purchased strip steaks randomly from grocery stores in California, Florida and South Dakota. Analysis in the same SDSU lab showed the same sized sample from those grocery store steaks contained only 13 percent of the selenium that could reduce the risk of cancer.

To think of it another way, the beef sampled randomly off the shelf at supermarkets delivered less than half — 47.3 percent — of the federal government’s recommended daily allowance of selenium. That recommended daily allowance is the amount of selenium required to maintain normal physiological processes, but it’s far less than the what’s needed to provide an anti-cancer benefit. In comparison, samples of beef finished on the medium- and high-selenium diets in South Dakota delivered 267.2 and 301.8 percent of the recommended daily allowance, respectively.

“These data clearly demonstrate that feeding high-selenium feeds to beef cattle during the finishing period can effectively increase the selenium concentration of beef,” Wright said. “Given the high concentrations of selenium in feeds grown in various locations in South Dakota, and the efficacy of increasing the selenium concentration of beef by feeding high-selenium feeds, beef producers in South Dakota may have an excellent opportunity for creating a value-added market niche.”

http://www.sdstate.edu/news/selenium-beef-study.cfm